The present invention relates to a frame structure for a vehicle, which constitutes part of a vehicle body and in which a reinforcement body to reinforce a frame body is provided inside the frame body which is formed to have a closed cross section.
A frame for a vehicle (a vehicle-body frame), such as a side sill or a pillar which constitute part of a vehicle body of the vehicle, such as automotive vehicles, is generally formed to have a closed cross section. It is also known that a reinforcement body is provided inside a frame body formed to have a closed cross section to reinforce the frame body. Japanese Utility Model Laid-Open Publication No. H4-067190, for example, discloses a structure in which a pipe-shaped reinforcement body which has a contour corresponding to a shape of an inner face of a side sill is fixed inside the side sill via an adhesive.
However, in a case in which the frame body is reinforced with the reinforcement body attached inside the frame body having the closed cross section as disclosed in the above-described patent publication, a weight increase may be improperly caused by the reinforcement body. Accordingly, it has been an important problem how to properly reinforce the vehicle-body frame, such as the side sill or the pillar, restraining the weight increase.
Meanwhile, in the vehicle, such as automotive vehicles, it has been desired that a torsional rigidity of the vehicle body is increased from view points of improving the vehicle's maneuverability-and-stability and/or the vehicle's ride. This is because an increase of the torsional rigidity of the vehicle body can properly restrain a bending deformation of the vehicle-body frame even in a case in which a torsional load which may be inputted to the vehicle body through attachment portions of a suspension device of wheels to the vehicle body during a vehicle traveling is transmitted to the vehicle-body frame, such as the side sill or the pillar, thereby generating a bending moment at the vehicle-body frame.